In my Zen study, I found a phrase that has helped me tremendously:

See everything as your teacher.

Everything.

When someone is upset with me, or being frustrating, they’re my teacher.

When I think I’m right and someone is telling me I’m not, they’re my teacher.

When I encounter anyone out in public doing something I don’t like, they’re my teacher.

Even setbacks.

The Stoics believed this too: setbacks are opportunities.

“If you are pained by any external thing, it is not this thing that disturbs you, but your own judgment about it. And it is in your power to wipe out this judgment now.” – Marcus Aurelius

And:

“Remind yourself that misfortunes can only be predicted for your body or your property but your mind is always available to turn it into good fortune by responding with virtue.” – Epictetus

Take every setback as an opportunity to learn, to grow, to practice.